1. Field of the Invention
The present invention relates to recording apparatuses that perform recording by causing a recording unit, such as a recording head, to discharge liquid droplets on a recording material. In particular, the present invention relates to a recording apparatus that can perform recording on recording materials of various kinds and thicknesses by adjusting a gap between the recording unit, such as a recording head, and the recording material.
2. Description of the Related Art
In the related art, serial-type recording apparatuses that perform recording by scanning a recording head in a direction (i.e., main scanning direction) extending crosswise to the conveying direction of a recording material (i.e., sub-scanning direction) is known. Such a recording apparatus records an image by using the recording head mounted on a carriage that moves in the main scanning direction. After a recording operation performed for one row, a paper feed operation is performed for feeding the recording material by a predetermined distance in the sub-scanning direction. By repeating these operations, recording is performed on the entire recording material. Of recording apparatuses of such a type, a recording apparatus configured to perform recording on thick recording materials, such as envelopes and cardboards, is known. When recording on a thick recording material, it is necessary to avoid rubbing of the recording head against the recording material since the gap between the recording head and the recording material is narrow. In contrast, with an increase in image quality over the recent years, when recording on specialty paper, such as glossy paper, it is necessary to further narrow the gap between the recording head and the recording material.
Japanese Patent Laid-Open Nos. 7-276736 and 2004-42346 of the related art discuss technologies for fulfilling both of these demands.
In the technology of the related art discussed in Japanese Patent Laid-Open No. 7-276736, a rotatable sliding member is attached to the top of a carriage unit and is configured to slide on a chassis of an apparatus main body. The sliding member has multiple slide faces with different distances from the center of rotation of the sliding member. These slide faces of the sliding member are slidable on the chassis. By rotating the sliding member to switch the slide faces slidable on the chassis, the carriage is rotated about a guide shaft, thereby adjusting the gap between the recording material and the recording head. When recording on a thick recording material, such as an envelope, the gap can be widened, whereas when recording on specialty paper, such as glossy paper, the gap between the recording head and the recording material can be narrowed.
In the technology of the related art discussed in Japanese Patent Laid-Open No. 2004-42346, cams are provided at opposite ends of the guide shaft, and the chassis has surfaces that are in contact with the cams. With this configuration, the guide shaft can be positioned in the sub-scanning direction relative to the chassis. By rotating the cams with a driving source, the height of the guide shaft can be adjusted while the position thereof in the sub-scanning direction is fixed.
In the technology of the related art discussed in Japanese Patent Laid-Open No. 7-276736, the sliding member attached to the top of the carriage unit is rotated to cause the carriage to rotate about the guide shaft, thereby adjusting the gap between the recording head and the recording material. Therefore, when in an adjusted position, the carriage is tilted with respect to the recording material, causing the gap to vary depending on different nozzle positions. This may degrade the quality of a recorded image.
The sliding member used for adjusting the gap needs to be provided separately from the carriage. Therefore, when recording on specialty paper, such as glossy paper, which particularly requires a high quality image to be recorded thereon, this sliding member is used for sliding the top of the carriage unit on the chassis. This means that this configuration unfavorably includes a component tolerance equivalent to a single component.
In the technology of the related art discussed in Japanese Patent Laid-Open No. 2004-42346, the guide shaft needs to be a cylindrical shaft. In addition, the cams provided at the opposite ends of the guide shaft, a spring for biasing the guide shaft downward, and the driving source for rotating the cams are required. Therefore, a sufficient torque for lifting the guide shaft, the cams, the spring, and the carriage upward is necessary. To create such torque, it is necessary to use highly functional components for a motor and a reduction gear train. This results in an increase in the cost of the recording apparatus.